JP-8-121122A shows a valve timing controller that is provided with a housing receiving a driving force from an crankshaft of the engine and a vane rotor accommodated in the housing to transfer the driving force to a camshaft. The vane rotor rotates in advance direction and retard direction to adjust an angle phase of the camshaft relative to the crankshaft. A cylindrical member is press-fitted into the vane rotor on one end surface thereof. The housing includes a front end plate that has a boss rotatably supporting the cylindrical member.
As shown in FIG. 5A, when the cylindrical member 210 is press-fitted into the receiving hole 220 of the vane rotor 200, an inner periphery of the receiving hole 220 is expanded so that the vane rotor 200 is warped in the axial direction as shown by arrows in FIG. 5B. This may causes a leakage of operating fluid between an advance chamber and a retard chamber.